Dynamo-electric machine



(No Model.) 2 Sheet eeeeeee 1.

W. L. SILVEY.

DYNAMO ELECTRIC MAGHINE.

No. 400,130. Patented Mar. 26, 1889.

[EVER/LEI UNITED STATES PATENT OFFICE.

IVILIJIAM Ii. SILVEY, OF CINCINNATI, OHIO.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 400,180, dated March 26, 1889. Application filed November 17, 1887. Serial No. 255,376- (No model.)

To all whom it may concern.-

Be it known that 1, WILLIAM L. SILVEY, a citizen of the United States, residing at Oincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Dynamo-Electric Machines, of which the following is a specification.

My invention relates to improvements in dynamo-electric machines in which a circular field-magnet is used in connection with a circular armature, and in the means by which I am able to make the field-magnet cheaply and in a substantial manner, and a machine designed to give almost double the output in amperes with almost the same number of volts that could be got out of the two-pole type of dynamo. In order to accomplish this result I have constructed a machine in which I never have less than four poles, and may have as many as twelve or more. In every case I have the same number of poles on the armature as on the field-magn et, and of course, the coil between the poles 011 the armature being of the undivided type, it is evident that I will have the same number of segments in my commutator as I have poles on my field magnet and armatnre'i. 0., a machine having four poles 011 the field-magnet and armature will have four segments in the commutator, and so 011. I11 this way I have a machine easy to build, and if it should need ropair it can be done at little expense.

Machines of the Gramme typehaving many segments in the commutator frequently get short circuits in the commutator between contiguous segments, in which case the coil which is short-circuited will create an abnormal current, and consequently heat the wire and char the insulation, which of course will disable the armature, if not entirely destroy it; but an armature constructed on my plan, in case two segments in the armature get short-circuited, there being no other coils in series with the coil to keep up the electro-motive force, it is evident that the armature at once ceases to make a current, and in this way all danger to the coil is removed. The reason of this is the fact that the resistance of the short circuit is practically nothing,while the resistance of the field-magnet circuit,which must be supplied in order to create any current in the armature, is considerable, Now, therefore, a current will divide between two circuits in proportion to their resistance.

Consequently the difference between the resistance of the field-magnet circuit and that of the short circuit is so great that nearly all of the current in the machine will flow through the circuit of low resistance, an d consequently there will not current enough flow through the field-magn et to keep the machine charged, and as a result the machine will cease to make any current. This will continue until the shortcircuit is removed, at which time the machine will make current as before. This short-circuiting and its result act as a safety device more perfect than any other means, and as a resultIhave never had a burnedout armature since I adopted this manner of construction.

Referring to the accompanying drawings, which are made a part hereof, similar letters referring to similar parts, Figure l is a front elevation of the machine with the hanger-arm B broken away 011 one end to show the manner of coring the pole-piece a. Fig. 2 is an end view diagram of the electric circuits. Fig. 23 is a perspective view of the armature, showing the manner of mounting the armature-blanks F, which constitute the armaturering, on the bolts with the triangular jamnut, Fig. 4, for pressing the blanks tightly together; and Fig. 5 shows an armature-blank as stamped out, and of which the armature is composed.

The field-magnet consists, essentially, of an iron ring, on which wedge-shaped polcpieces are cast. This wedge-shaped pole-piece has its narrowest point projecting inward, in front of which the ring-armature F revolves. This field-pole is made as narrow as possible, in order to carry the magnetism of the field-magnet, for I have found that a multipolar machine does not require the poles to expand as much on their armature-face as a machine having only two poles.

In the construction of my field-magnet I cast the entire ring in one piece with a dry sand core in two or more of the poles, so as to make a hole, a, which extends the entire length of the pole. After the casting has been bored out and finished up ready for the wiring I drive wedges into the cored holes and split the casting into two or more parts. This allows the field-magnet to be then wound on a machine, whereas if the ring were solid it would have to be wound with a shuttle, which is a very slow and difficult piece of work. By this simple means of coring the poles I am able to wind a field-magnet for less than one-half what it would cost were it cast solid or inseparable. After the field-magnet has been split there are ragged edges where the iron was broken. These act as sutures to keep the parts from slipping on each other, and they also make a more perfect joint magnetically than it would be possible to obtain were the faces plan ed. In fact, a broken joint is much more solid and better than a planed joint. This is one part of my invention on which I put particular stress. The parts of the field-magnet are held together by the expanded ends of the hanger-arm B, one of which is bolted to each end of the field-magnets for the supportof the shaft. The armature is composed of laminated iron rings separated from each other by rings of paper of the same shape. 011 these rings, which are stamped out of sheet-iron, at regular i11- tervals there is a wedge-shaped pole-piece, the base of the wedge projecting outward, through the center of which ahole is stamped. Through these holes there pass rods to keep the armature-rings firmly secured together and act as carriers. These rods project at each end and pass through the triangular jam-nut F, which serves the purpose of pressing the blanks of paper and iron together and keeping the brass end plates from comin g in contact with the coils, and then through corresponding hole in brass flange-plates Z, which are secured to the shaft, so that when the parts are all mounted together they con stitute a drum of the most solid construction, and the depressions on the armature being wound full of wire there are few or no projections to catch against currents of air, and therefore the loss of mechanical power from this cause is almost entirely overcome. The armature-coils are all wound in one direction and joined together into a continuous circuit. At the junction between the coils there are joined leading-wires g g which connect alternately to the difierent junctions, and the coils all being wound round in one direction, while the poles 011 the fieldmagnet are of alternately north and south polarity, it is evident that the leading-wires will collect currents of opposite polarity. These j unction-wires are joined to two shaftwires, h h, which pass out through the shaft and connect to the alternate segments of the commutator, from which the current escapes by the brushes (1 d to the fieldmagnet and outside circuit.

It will be observed that the field-magnet is compound wound for the purpose of automatic regulation. For arc lighting the finewire coils are so proportioned that the coarse wire is only required to create a sufficient electro=motive force to overcome the resistance of one are. The fine wire, which is of high resistance, receives but little current, and consequently does but little work; but as the resistance of the external circuit increases more current is diverted into the fine-Wire coil, and consequently the armature generates a correspondingly high current until the limit of capacity is reached. This is my manner of regulation of arc-circuits.

For incandescent circuits, or where a constant potential is desired with a variable quan= tity of amperes, I wind my field-magnet in such proportion between the fine wire and coarse wire that the fine wire is only capable of generating an electro-motive force of, say, one hundred volts and five amperes. This current escapes through the coarse=wire coils to the line. As more lamps are thrown into the main line in multiple-arc circuit, the re= sistance in that circuit is correspondingly reduced. As the resistance in this circuit decreases, more current flows through that on cuit and less through the shunt or fine-wire coils on the field-magnet, and as a consequence the machine becomes practically self-regulating. The current escapes from the commutator to brush (1, where it divides into two circuits, before mentioned. The fine-wire circuit S flows to the field-magnet coils which are joined in the series, each alternate coil being wound in a different direction. This makes the pole-pieces all consequent poles on the field-magnet. The current in the fine wire after traversing all the field-magnet coils returns by the fine wire T to brush d and commutator E. The coarse-wire coil traverses the field -magnet in the same direction as the fine-wire coil. The current enters fieldmagnet at brush (1' and terminal wire V, and after traversing all the field-coils L in a direction the same as the fine=wire coils, before described, escapes by terminal wire to bind= ing-post K, thence to line and lamps Q R, from whence it returns to binding post P, and thence by leading-wire U to brush (1, thus completing its circuit.

By constructing a machine in the form enr bodied in my present invention I utilize both ends of my field-magnet core, and also the induction of one side of my field-magnet coils on the armature. In this way I get the greatest electrical efficiency, and also a machine which is extremely light and easy to construct.

Having described my invention, what I claim as new, and wish to secure by Letters Patent of the United States, is

1. A field-magnet for dynamo-electric machines, cast in a single piece and broken into two or more parts by means of Wedges driven into holes where the divisions are desired for the purpose of facilitating the winding of the coils of wire thereon.

2. The field-magnet A, having the hole 0.

therein for facilitating the fracture or divisragged, broken, or irregular joint for formion of the magnet for the purpose of winding. ing' a more perfect magnetic joint, as set forth.

3. The field-magnet of a dynamo-electric machine, the pole-pieces broken apart and 5 united by sutures, as set forth. Witnesses:

4. The field-magnet of a dynan10-e1ectric WILL. MITTENDORF, machine, the polar extensions united by a- OHAS. HILL.

VILLIAM L. SILVEY. 

